fix(simulator): disable Grafana phone-home for air-gap hygiene

Grafana was checking grafana.com for updates and sending usage
reporting by default - the only outbound traffic in the whole stack.
Verified empty latestVersion and no established external connections
from any container after the change.

simulator/docker-compose.yml

@@ -58,6 +58,10 @@ services:
       GF_AUTH_ANONYMOUS_ENABLED: "true"
       GF_AUTH_ANONYMOUS_ORG_ROLE: Admin
       GF_AUTH_DISABLE_LOGIN_FORM: "true"
+      # Air-gap hygiene: no phone-home, no update checks, no plugin fetches
+      GF_ANALYTICS_REPORTING_ENABLED: "false"
+      GF_ANALYTICS_CHECK_FOR_UPDATES: "false"
+      GF_ANALYTICS_CHECK_FOR_PLUGIN_UPDATES: "false"
     volumes:
       - ./monitoring/grafana/provisioning:/etc/grafana/provisioning:ro
       - ./monitoring/grafana/dashboards:/var/lib/grafana/dashboards:ro